Phonograph-reproducer



(Model.)

T. A. EDISON.

PHONOGRAPH REPRODUGER.

No. 394,106. Patented Dec. 4, 1888..

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UNiTEn STATES PATENT OEEICE.

THOMAS A. EDISON, OF LLEVELLYN PARK, NEV JERSEY, ASSIGNOR TO THE EDISONPHONOGRAPH COMPANY, OF NE\V JERSEY.

PHONOGRAPH-REPRODUCER.

SPECIFICATION forming part of Letters Patent No. 394,106, dated December4, 1888.

Original application tiled November 26, 1887, Serial No. 256,189.Divided and this application tiled March 2, 1888. Serial No. 265,888.(Modelt) To all whom it may concern.-

Be it known that I, THOMAS A. EDISON, a citizen ot' the United States,and a resident of Llewellyn Park, in the county of Essex and State ofNew Jersey, have invented a certain new and nset'ul Improvement inPhonograph- Reproducers, (Case No. Tol, division ol Case No. 74h) otwhich the following is a specilicati on The ol'ijeet I have in view isto produce an efficient reproducii'ig-instrument l'or phonographs; andmy invention consists in the several novel features and comli inations,as fully hereinafter explained, and pointed out by the claims.

In the accompanying drawings, Vforming a part hereof, Figure] Vis abottom or rear view ot' the reprinlucer on an enlarged scale, and Fig. 2a seetioiial view of' the same.

O is a metal plate forming the body of the reproducer. It has anopening, n, passing centrally through it, to which the listeningtube ol"the phonograph is applied. The plate O is ria-essed at its back, and hasstretched across it a diaphragm, O', which is preferably a thin animalmembrane. This diaphragm is secured in place by a ring, n', which issecured to the back ol" the plate O, while the diaphragm is stretclnldby another ring, uwhieh has a neck screwing into the opening u ot theplate, and is capable ot' being turned by a tool, so as to stretch thediaphragm O more or less. To one edge of the ring n is secured a linespring-wire, u3,whieh is long enough to reach t" rom the point where itis secured to the center otl the i'liaphragm, and has its inner endturned downwardly, as shown, to lollow the spiral line ot' indentationsupon the phonogram. The inner end ot' this s1ning-wire fui is attachedto the center ot' the dialihragm by a strip, ut, of rubber. The tendencyot the spring-wire is to bend away from the diaphragm, so that itstrains the small rubber strip n4 and places the diaphragm under aninitial tension. The

movement ot' the point ol' the wire u* in reproducing is so slight thatthe strain is never wholly removed from the rubber strip ut, and hencethe diaphragm always under tension, which tends to draw it outwardly atthe center. This makes the instrument exceedingly sensitive and capableof reproducing sounds accurately. The end ot the wire n3 being roundedand burnished, it will not obl iterate the phonog am-record, even thoughthat record is made in quite soft niaterial.

I have found that by connecting the reproducing-point with the diaphragmby a strip ot' elastic material-such as rubber held under tensiontheproper wave motion is transmitted to the dialiihragm, but the scratchingnoises which seem to require molecular transmission are largelyobliterated.

lVhat I claim isl. A phonograph-reprodueer having, in coinbination,adiaphragm and a reproducing-point connected with the diaphragm by astrained elastic strip, substantially as set forth.

2. A phonographreprodneer having, in combination, a diaphragm andreproducingpoint, a spring tending to'throw the reprodueing-Iiioii'itaway from the diaphragm, and an elastic strip connecting the point withthe diaphragm, wherelrv a spring-tension will always exist between thepoint and the diaphragm, substantially as set forth.

3. A phonograph relnoducer having, in combination, a diaphragm and aspring-wire i secured at its outer end and projecting toward theeenterotl the diaphragm and turned to t'orm a reproducing-point, saidspring-wire tending to spring away l'rom the diapln'agm, and a strip otiinlia-rubber connecting the end ot' the spring-wire to the center ofthe diaphragm, substantially as set lorth.

l. A phonograph reprodueer having, in ctnnbination, a diaphragm ofanimal membrane, a reproduci11g-point, a spring tending to throw thereproducing-point away from the diaphragm, and an elastic stripconnecting said point with the center of the diaphragm, substantially asset forth.

5, A phonograph reprodnoer having, in This speciioaion Signed andwitnessed this combination, a diaphragm of animal inonl- 20th day ofFebruary, i888. brano, a ring` for stretching such diaphragm, 1

a reproducing' point', a spring` tending to THOS. A. EDISON. 5 throw thereproducing-point away from the diaphragm, and an elastic stripConnecting XVitnesSes:

said reproducing-point with the diaphragm, XVILLIAM PELZER,

substantially as set forth. E. C. ROWLAND.

